Meet the world's longest privately owned vessel. The Azzam is a whopping 590 feet from end to end, about two football fields long. Designed by Milan-based Nauta Yachts and launched in April 2013 by Germany's Lurssen Yachts, the $609 million superyacht has 94,000 horsepower and can travel at 30 knots (34.5 mph). The identity of its owner, while rumored to be a member of the Saudi royal family, remains a mystery.

Adastra

The stunning space-age Adastra glides over the water on its sleek hull and twin "wings." This $15 million stunner designed by John Shuttleworth recently won three prizes at the ShowBoats Design Awards in Monaco, including Best Naval Architecture.

Made of lightweight carbon material, the 139-foot Adastra can travel up to 26 mph as only about 20 percent is actually submerged in the water. The interior features plush cabins, a saloon, and aft bar. In a tech twist, it can be remotely controlled by iPad.

Adastra interior

While perhaps a tad too brightly illuminated, the saloon area on the Adastra's main deck seems perfect for a Bond-style supervillain. In reality, the yacht is owned by Hong Kong shipping magnate Anto Marden and his wife Elaine.

Regina

Known for its appearance as the Chimera in the James Bond film "Skyfall," the Turkish-built Regina is a 183-foot deluxe schooner that can accommodate 12 people in six staterooms, as well as seven crew members. It comes with all the modern tech conveniences such as 3D LED TV, Blu-ray DVD, Nintendo Wii, and PlayStation 3, as well as enormous sun decks and a wood-paneled saloon. It's for sale by Fraser Yachts at $12.8 million.

Quattroelle

Another Lurssen creation, the beautiful Quattroelle was built in 2012. At 288 feet long with five decks, Quattroelle has a striking exterior designed by Italy's Nuvolari & Lenard. It can accommodate 12 guests in six suites and will sail the Caribbean and Mediterranean seas, where it can be chartered starting at a mere 1 million euros ($1.3 million) per week.

Quattroelle pool

Amenities aboard the Quattroelle include large deck areas for sun tanning, a spa, a hair salon, a movie theater, an art gallery, and this relaxing pool to splash about in while drinking up the panoramic views.

Venus

The 256-foot Venus was conceived by Philippe Starck and Steve Jobs before the Apple mogul's death, and its boxy design continues to turn heads. The $140 million, all-aluminum vessel is mostly controlled by seven iMacs.

In his biography of Jobs, Walter Isaacson wrote: "As at an Apple store, the cabin windows were large panes, almost floor to ceiling, and the main living area was designed to have walls of glass that were 40 feet long and 10 feet high. He had gotten the chief engineer of the Apple stores to design a special glass that was able to provide structural support."

They call it A

Designed by Philippe Starck and Martin Francis, the 390-foot A is named after the first initials of its owners, Russian billionaire Andrey and Aleksandra Melnichenko. Seen here through the leaves along the French Riviera in 2011, it was constructed at a reported cost of some $300 million by German shipbuilder Blohm + Voss and features a distinct knife-shaped prow. The lavish interiors include many mirrors, crystal, stingray hides, and heavy security, such as a 2,583-square-foot master suite (with a rotating king-size bed and a retracting 60-inch plasma TV) that is encased in bomb-proof, 44-milimeter glass.

Solandge

Known as Project Niki before its launch, the Lurssen-built Solandge boasts a large swimming pool, a helicopter pad, and super-posh staterooms for 12 guests. The interiors, by Aileen Rodriguez, apparently feature design elements with 49 types of stone and 33 types of wood.

Eclipse

The Eclipse, now the second-largest private yacht in the world following the Azzam, docks at a New York pier in February. The boat, which measures 536 feet in length and is estimated to cost a whopping $1.5 billion, is owned by Russian billionaire Roman Abramovich. Its defenses include armor plating, bullet-proof windows, and missiles.